The present invention relates to an athletic shoe midsole design and construction, and more particularly, to a midsole assembly having a vent or vent hole formed in a midsole.
The sole of an athletic shoe is generally comprised of a midsole and an outsole. The midsole is typically formed of soft elastic material in order to ensure adequate cushioning properties. The outsole is fitted under the midsole and directly contacts with the ground.
Preferably, ventilation of a shoe is required in a degree when wearing a shoe. Various kinds of shoes with vent holes have conventionally been proposed.
For instance, the Japanese patent application laying open publication No. 8-131204 discloses a plurality of transverse holes formed at a body portion of the bottom member of a shoe and a plurality of vertical holes also formed at a body portion of the bottom member. The vertical holes communicate with the transverse holes and penetrating through the insole. The Japanese utility model application examined publication No. 63-43923 shows a plurality of through holes penetrating through the upper member of a sole in the thickness direction and a plurality of grooves formed at the lower member of the sole. Each of the grooves corresponds to each of the through holes.
In both cases, the air flows into a shoe through the transverse holes and the vertical holes, or the through holes and the grooves. Thus, ventilation of the inside of a shoe is acquired.
In the prior art construction, however, transverse holes or grooves are merely formed on the body portion or the lower member made of rubber or the like. Thus, in the case of an athletic shoe to which impact load is applied at the time of impacting the ground, the transverse holes or the grooves are deformed and crushed by the compressive deformation of the body portion or the lower member. As a result, ventilation of the inside of a shoe is interrupted.
The object of the present invention is to provide a midsole assembly for an athletic shoe that can ensure ventilation of a shoe.
The present invention provides a midsole assembly for an athletic shoe.
In one embodiment, a midsole assembly comprises a midsole formed of soft elastic material, a transverse hole extending laterally and formed at least at the heel portion of the midsole, a retention member for retaining the shape of the transverse hole, and a vent hole extending vertically and communicating with the transverse hole and having an open end on the plantar contact face of the heel portion of the midsole.
In another embodiment, the profile of the retention member conforms to at least a portion of the sectional shape of the transverse hole and the retention member is arcuate, semi-circular, or circular in cross section.
In still another embodiment, the retention member is formed of a corrugated sheet interposed in at least the heel portion of the midsole, and the transverse hole is formed at the contact regions of the midsole with the corrugated sheet.
In a further embodiment, a vertically extending through hole is formed at a midfoot portion, or a plantar arch portion of a midsole, and a longitudinally extending vent passage, in connection with the vertically extending through hole, is formed at a forefoot portion of a midsole. Besides, a vertically extending vent hole, in communication with the longitudinally extending vent passage, is formed at the forefoot portion and open at the plantar contact face of the forefoot portion of the midsole.
In a still further embodiment, the openings of the vertically extending vent holes, formed on the bottom side of the forefoot portion, are aligned in a general shoe width direction, and a groove extending in a general shoe width direction, in connection with these openings, is formed on the bottom side of the forefoot portion.
In an additional embodiment, a vertically extending through hole is formed at a midfoot portion of a midsole, and a groove extending in a general shoe width direction, in communication with the vertically extending through hole, is formed at the midfoot portion.
In a preferred embodiment, a midsole assembly comprises a midsole formed of soft elastic material, a corrugated sheet interposed in at least the heel portion of the midsole, a plurality of laterally extending transverse holes formed at the contact regions of the midsole with the corrugated sheet, and a plurality of vertically extending vent holes, in communication with the transverse holes, formed and open at the plantar contact face of the heel portion of the midsole. A midsole assembly of this embodiment further comprises a vertically extending through hole formed at the midfoot portion of the midsole, a longitudinally extending groove, in connection with the vertically extending through hole at the midfoot portion, formed at the forefoot portion of the midsole, and a plurality of vertically extending vent holes, in communication with the longitudinally extending groove at the forefoot portion, formed at the forefoot portion of the midsole and open at the plantar contact face of the forefoot portion. A midsole assembly of this embodiment still further comprises a concave, or a recess, formed at an opening portion of the vertically extending through hole on the bottom side of the midfoot portion, and a cover portion covering a portion of the concave, formed at a portion of the corrugated sheet and disposed oppositely to the opening portion of the vertically extending through hole.
In use of a shoe, the air is introduced into the shoe through a transverse hole formed at the heel portion of a midsole and a vent hole communicating with the transverse hole, and thus, ventilation can be acquired inside the shoe, especially at the heel portion. Moreover, in this case, because a retention member for retaining the shape of the transverse hole is provided, the transverse hole can be prevented from being deformed and crushed even when a midsole is compressively deformed by the impact load at the time of impacting the ground. Thus, even in an athletic shoe, ventilation can be realized and secured.
When the retention member is formed of a corrugated sheet, which is hard to be deformed, by the action of the corrugated sheet, compressive deformation of the midsole is restrained and the shape of the transverse hole is maintained. Thus, the transverse hole can be prevented from being deformed and crushed even in the case of impact loading onto the midsole. Also, the heel portion of the midsole can be prevented from being deformed transversely by the action of the corrugated sheet, which makes it possible to achieve running stability at the time of impacting the ground.
Moreover, the corrugated sheet allows for smooth restoration of the transverse hole after deformation, and as a result, efficient ventilation can be attained by the pumping action. Furthermore, when the corrugated sheet with higher elasticity is used, the transverse hole becomes hard to be worn, and ventilation of a shoe can be maintained during a prolonged period.
When a vertically extending through hole is formed at a midfoot portion, or a plantar arch portion, the air is introduced into a shoe through this through hole, and thus, ventilation can be attained inside a shoe, especially at the midfoot portion. Moreover, in this case, because the air is introduced into a shoe through the vertically extending through hole to a longitudinally extending air passage such as a groove at the midfoot portion and to an air vent hole at a forefoot portion, ventilation can be attained inside the shoe at the forefoot portion as well.
When the openings of the air vent holes on the bottom side of the forefoot portion are aligned in a width or lateral direction, and a laterally extending groove, in communication with these openings, is formed on the bottom side of the forefoot portion, flexibility of the forefoot portion of the midsole can be improved by this groove.
When a laterally extending groove and a vertically extending through hole are formed at a midfoot portion, the air is introduced into a shoe through this groove and this through hole, and thus, ventilation can be acquired inside the shoe, especially at the midfoot portion.
When a corrugated sheet, or a wavy sheet, is provided in the midsole, compressive deformation of the midsole is restrained, and the shape of a transverse hole is maintained. Thus, even in the case of impact loading onto the midsole, deformation of the transverse hole can be prevented and ventilation can be secured inside a shoe, especially at the heel portion. Besides, transverse deformation of the heel portion of the midsole can be prevented and running stability can be secured at the time of impacting the ground.
Also, in this case, ventilation is attained at the midfoot portion as well through a vertically extending through hole. Besides, ventilation at the forefoot portion is acquired through a vertically extending vent hole formed at the forefoot portion.
Moreover, the opening portion of the through hole on the bottom side can be prevented from being exposed to the ground by a cover portion, which is disposed oppositely to the opening portion of the through hole, and covers a portion of a recess on the bottom side of the midfoot portion.
Thus, water, sand, dust or the like outside a shoe is restrained from entering the inside of the shoe via a through hole at the midfoot portion at the time of impacting the ground. As a result, this shoe can be used as an outdoor shoe.